Dust control of frac sand by applying a solution of water and polymers, such as cationic polymers, is disclosed in recently published applications by Baker Hughes (2013/0192835) and (2015/0104647). Applying dust control solutions onto the surface area of the sand is a well-known technology. These patent documents are incorporated by reference herein. Lab test showed that the Baker Hughes technologies were not effective to keep the measured average dust concentration of treated materials in airborne environment less than 0.05 milligrams per cubic meters, especially, the dust suppression effectiveness is temporary and short-life with less than four days, often if at all, for not more than a day or so. Such short time dust control is unacceptable in the hydraulic fracing field. In general, at least two to three days are required to make sure that the treated frac sand still has the needed potent of dust suppression efficiency. In addition, a re-drying operation in most dust suppression operation is needed in order to effectively flow the chemically treated frac sand. Without a re-drying operation, the frac sand will create operational issues such as arching, adjacent particles sticking to each other. As such, a chemical solution is needed to have a prolonged dust suppression efficiency held for at least four days and have a dust free frac sand product with an average dust concentration of less than 0.05 milligrams per cubic meter without a need for re-drying while still maintains its flow free characteristics during transportation and at hydraulic fracing onsite operation, i.e. a moisture content of less than 0.30 percent. There is a need for a “long term dust free” proppant.